Metallic fiber pipe fitting and method of making same



H. SWEET Aug. 7, 19,34;a

METALLIC FIBER PIPE FITTING AND METHOD OF MAKINGSAME Filed Feb. 2, 1932 method of making the same.

Patented Aug. 7, 1934 PATENT oFEigcE METALLIC FIBER PIPE FITTING AND METHOD F MAKINGTSAME Harry Sweet, Berlin, N. H., assignor to Brown Company, Berlin, N. H., 'a corporation of Maine Application February 2, 1932, Serial No. 590,423

Claims.

This invention relates to liber-pipe fittings and Fiber piping for various uses has many recognized advantages. Such piping may be made in various ways, such for example as by winding a sheet of wet wood pulp about a mandrel under pressure'until. the desired wall thickne is obtained, and drying the resulting tube thus formed. The tube may be treated by impregnation with pitch or other waterproong material to render it water repellant. By treating the interior of the tube with a suitable type of waterproofing material such as blown or oxidized asphalt, an eifective lining is readily formed which renders the tube suitable for use as water piping. While fiber piping has come into extended use and has been employed y for an increasing variety of purposes, the question of satisfactory couplings has always been a considerable problem, various solutions of which have been employed with varying degrees of satisfaction. This invention relates to a type of fitting which can be embodied not only in suchl ttings as elbows, T-joints, crosses, and Y-joints, but also may take the form of an end fitting for a section of liber coupling adapted to strengthen the end portions of the section and to facilitate the formation of `a strong fluid-tight joint with another similarly equipped section of pipe. In forming fittings according to the invention, the end portions of one or more sections of ber tube are suitably shaped as hereinafter set forth in more detail; these end portions are then insertedk in a suitable die or mold; then molten metal is cast in the mold about the tube end or ends which are held in the mold, the metal entering the small surface irregularities of the bers, aswell as any additional recesses formed therein for locking purposes, and shrinkingtightly against the exterior of the tube end or ends in the course of solidifying. In casting end fittings on tube sections to serve as coupling members, these fittings may be suitably molded in the casting operation so as to present an exterior surface vwhich is screw-threaded or otherwise formed to interact with a corresponding coupling member. Cast metal fittings of the kind hereinafter described can be used to advantage not only on felted fiber tubing of the type referred to, but also on other varieties of ber pipe such as wood stave pipe or helically wound paper tubing.

For a. more complete understanding of the invention, reference may be lhad .to the description thereof which follows, and to the illustration 'thereof of certain embodiments on the drawing, of whichr- Figure 1 shows in section an end portion of a section of liber pipe having a coupling fitting thereon embodying the invention.

Figure 2 is a cross-sectional view Aof an end portion of a pipe section together with a suitable molding means by'which a coupling fitting may be cast on the pipe end.

Figure 3 is a sectional View of va T-joint embodying the invention.

Figure 4 is an elevation of an elbow. 65

Figure 5 is an elevation of a cross.

Figure 6 is an elevation of a Y-joint.

In making the coupling tting illustrated in Figure 1, the end portion of a section 10 of fiber pipe may be provided with a. number of recesses 11 which, as shown on the drawing, may take the form of circumferential grooves. A sleeve 12 of suitable metal is thereupon cast about the end portion of the pipe 10, the metal entering the grooves 11 to interlock therewith and to provide longitudinal strength for the nished joint. It is evident that the recesses 11 may consist of one or more dents or depressions in place of the grooves, any such recess being eifective to receive the molten metal `tol form a locking tongue or 30 knob of metal projecting inwardly intov the wall of the pipe section. A suitable mold 20 may be employed to receive the pipe end about which the fitting is to be cast. The interior surface of this mold may be suitably shaped with a screw-thread matrix as at 21 so that a screw-thread will be cast on the exterior surface of the sleeve 12. In order to keep the interior of the tube 10 clear of the metal, a suitable plug orA core 22 may be employed in 'conjunction with the mold 20. The melting point of the metal employed in the formation of the sleeve 12 must be as low as possible in order to minimize the charring 'of the fiber and also to avoid as far as possible diiilculties arising from the boiling of pitch with which the tube may Vhave been previously impregnated. To this end, lead or an easily melting alloy of lead may be employed. If desired, other metals or alloys such as aluminum, brass, yor an equivalent, can be employed. It is desirable that if the pipe is intended for use'- as water piping, the metal employed be o1' such a nature as to resist rust or y. corrosion. The ythreaded iitting may be employed to enter a corresponding coupling collar (not shown) which may be of metal, ber, or any other convenient material. 'I'he metal sleeve 12 is preferably extended over the end face 25 of the tube 10, as at 26, so that the end face of the tube is protected from mechanical injury and from deterioration through possible access of 110 los 4waterproofing compound such as blown asphalt. This coating preferably extends over the boundary line 28 between the ber and metal at the end of the pipe 10. A coating of soft asphalt or mastic may then be applied to the end of the pipe tting as at 30, this mastic covering the end face of the metal sleeve l2 and extending within the pipe to lap the end of the inner coating 2'7 and also lthe boundary 28 or .junctionA line between the ber and metal. When the pipe section is joined to another section, this mastic coalesces with a similar mastic coating on the end of the other pipe section so as to seal the joint between the end faces of the abutting ttings.

Figure 3 shows in section a T-joint embodyingv -the invention. In making fa. joint of this type, a

section of ber pipe 40 is notched as at 41 to receive the suitably shaped end portion 42 of a -second piece of ber piping 43. The latter may be notched or grooved as at 44 for locking purposes as hereinbefore described. The pipe sections 40 and 43 are then held together in a suitable mold in the position shown and a sleeve 45 of metal is poured into the mold to surround the joined portions of the pipe sections, so that a strong T-tting is thereby constructed. 'llihere-l after, the interior of the tting may be suitably supplied with a coating 46 of waterproong'flmaterial, this coating serving to seal the li'nes of juncture between the two pipe sectionsand to provide a smooth interior surface for the tting.

To form an elbow as illustrated in Figure 4,4

a sufficient number of wedge-shaped pipe sections may be placed together to connect ends of a pairof pipe sections arranged at an angle to 'each other as shown, this structure being supported in a mold and surrounded bya'. unitary casting or sleeve of metal.

- In like manner, `four sections of ber piping Leeaoee may be shaped at their ends and held together in a suitable mold to form a cross coupling as illustrated Figure 5.

Figure e shows in elevation a Y-joint tting iormed by holding suitably shaped ends `of three pipe sections together and casting a unitary metal sleeve about the joint to form the tting as shown. En each case, after the exterior metal sleeve has been cast, the interior of the tting may be provided with a smooth coating of suitable waterproong material to seal the lines of juncture between the section ends. y

It is evident that other shapes of ttings can be `readily constructedin similar fashion.

l claim:-

i. A fitting for ber piping, comprising a sec- -tion of ber pipe, and almolded'sleeve of metal having a relatively low melting point cast about a portion of its exterior surface.

2. A tting for ber piping, comprising a section of ber pipe having an exterior recess, and a molded sleeve of metal having a relatively low melting point cast about a portion of the exy terior sur-faceof said pipeand lling said recess.

3. A tting for ber piping, comprising a section of ber pipe, and a molded sleeve vof metal (having a relatively 10W` melting point cast on an end'portion of said pipe, said sleeve having a screw-thread molded -in the exterior surface thereof.

4. A fitting for ber piping, comprising a vsection oi?l ber pipe having an exterior recess advvjacent to an end thereof, and a molded sleeve sealing the surface boundary 4between the ber and metal.

' vHARRY' SWEET.

mastic covering the end edge of the tting and 

